Known methods and systems for establishing a trace on an identified telephone number have, in general, been cumbersome and time-consuming thereby, often wasting valuable time in a situation where time is of the essence. More particularly, some known methods and systems for establishing a trace require manually programming central office switches in a geographic area. For example, if a trace is to be established for calls originating in the Chicago area, such a task typically requires three persons about three hours each to manually perform the task. This wastes precious time in a situation, such as a kidnapping, where time can not be wasted. In addition, as with any system that requires manual programming, errors may be made which would compromise the trace and lead to valuable information being lost.
Other known call tracing methods and systems require that an incoming call actually be answered and that the answering party initiate the trace. For example, U.S. Pat. No. 4,591,665 (Foster et al.) disclose a method of providing customer originated call tracing. If a customer receives an obscene or nuisance call, for example, the customer enters a code indicating that such a call has been received. The identity of the calling party is identified to authorities in response to the action by the customer. Such a system has obvious drawbacks including the potential for abuse by a called party. Such abuse would waste valuable time on the part of the authorities and detract authorities from where their resources are most needed. Other systems use a caller identification type of tracing commonly referred to as caller i.d. U.S. Pat. No. 4,754,475 (Pintos et al.) discloses a calling line tracing system and identification detector which identifies of a calling party without the called party ever lifting the telephone receiver. Other systems forward an incoming call to a called party's pager including caller i.d.-type information. See, for example, U.S. Pat. Nos. 5,644,626 (Carlsen et al.); 5,692,038 (Kraus et al.) and 5,694,453 (Fuller et al.). A drawback with such caller i.d. type devices is that the calling party may block the identification of the calling number typically by entering a code using the keypad of a phone before a call is made.
It is thus desirable to provide a call tracing method and system that is simple to implement, significantly reduces the time for its implementation, and provides accurate information in less time than known call tracing methods and systems. It is also desirable to provide a call tracing method and system that can cancel an implemented call trace quickly. It is also desirable to provide an automated call tracing method and system that can be automatically implemented and canceled at a site remote from the switches of central offices thereby eliminating direct manual programming of the switches at the central offices. It is also desirable to provide a call tracing method and system that does not require any action by the called party.